The present invention relates generally to laser scanning micrometers which optically measure a dimension of an object and more particularly, to a miniaturized laser scanning micrometer for hand-held measurements. While the present invention is generally applicable for making precision hand-held measurements, it is particularly applicable to hand-held measurements made in an operating room to measure in vivo characteristics and specifically patency of grafted blood vessels.
Microvascular reconstructive surgery is currently limited by the ability of the plastic surgeon to assess vascular patency in vascular grafts and transplanted skin flaps. Although instrumentation is available for assessing flow in large vessels, it is not readily applicable for determining patency in microvascular systems. For example, ultrasound probes have insufficient resolution for small vessels while other devices, such as cuff flow probes, have proven to be cumbersome and unreliable. Thus, doctors must rely on their sense of "feel" for evaluation of such surgical procedures.
To overcome these difficulties and provide a usable and reliable instrument for surgeons, investigations have been performed in recent years into the use of industrial helium-neon (HeNe) laser scanning micrometers to measure, in vitro: the diameter and dynamic radial wall motion of pulsating arteries; compliance of host vessels and graft vascular prostheses; suture-line stresses; and, geometric profiles of stenotic vessels. Such investigations have been very promising and have demonstrated the ease of operation of such micrometers, their repeatability, reliability and simplicity of calibration. Unfortunately, the size, weight and scanning structure of the industrial HeNe laser scanning micrometers precludes their use as operating room instruments.
Accordingly, there is a need for a miniaturized laser scanning micrometer for performing precision hand-held measurements, for example in an operating room to measure in vivo characteristics and specifically patency of grafted blood vessels.